Mozart: Implement hit testing.

services/gfx/compositor/graph/snapshot.cc

Index: services/gfx/compositor/graph/snapshot.cc
diff --git a/services/gfx/compositor/graph/snapshot.cc b/services/gfx/compositor/graph/snapshot.cc
index 66f44e987422516606efa5d2465250f974517fa9..8371cf7a472999a87420bab68cdc8fdcda2bb15a 100644
--- a/services/gfx/compositor/graph/snapshot.cc
+++ b/services/gfx/compositor/graph/snapshot.cc
@@ -5,9 +5,11 @@
 #include "services/gfx/compositor/graph/snapshot.h"
 
 #include "base/logging.h"
+#include "mojo/skia/type_converters.h"
 #include "services/gfx/compositor/graph/scene_content.h"
 #include "services/gfx/compositor/graph/scene_def.h"
 #include "services/gfx/compositor/render/render_frame.h"
+#include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "third_party/skia/include/core/SkRect.h"
 
@@ -25,21 +27,26 @@ std::shared_ptr<RenderFrame> Snapshot::CreateFrame(
     const mojo::Rect& viewport,
     const mojo::gfx::composition::FrameInfo& frame_info) const {
   DCHECK(!is_blocked());
+  DCHECK(root_scene_content_);
 
-  SkRect sk_viewport =
-      SkRect::MakeXYWH(viewport.x, viewport.y, viewport.width, viewport.height);
+  SkRect sk_viewport = viewport.To<SkRect>();
   SkPictureRecorder recorder;
   recorder.beginRecording(sk_viewport);
-
-  const NodeDef* root_node = root_scene_content_->GetRootNodeIfExists();
-  DCHECK(root_node);  // otherwise would have failed to snapshot
-  root_node->RecordPicture(root_scene_content_.get(), this,
-                           recorder.getRecordingCanvas());
-
+  root_scene_content_->RecordPicture(this, recorder.getRecordingCanvas());
   return RenderFrame::Create(skia::AdoptRef(recorder.endRecordingAsPicture()),
                              sk_viewport, frame_info);
 }
 
+void Snapshot::HitTest(const mojo::Point& point,
+                       mojo::gfx::composition::HitTestResult* result) const {
+  DCHECK(result);
+  DCHECK(!is_blocked());
+  DCHECK(root_scene_content_);
+
+  root_scene_content_->HitTest(this, point.To<SkPoint>(), SkMatrix::I(),
+                               &result->root);
+}
+
 bool Snapshot::IsNodeBlocked(const NodeDef* node) const {
   DCHECK(!is_blocked());